Wind Energy. It’s great for the environment, right? No greenhouse-gas emissions. No radioactive waste to dispose of. Completely renewable so there’s never any risk at all of exhausting its supply.

Even in this era of seemingly endless acrimony among the political parties of the United States, there is actually strong agreement that wind energy is a good thing, for all of the reasons cited above and many others. In a survey conducted by the American Wind Energy Association in April, 84% of Republicans, 93% of Democrats, and 88% of Independents expressed their belief that increasing the amount of energy the U.S. produces from wind is a good idea. That kind of agreement is just unheard of these days.

So why have environmental groups taken to filing lawsuits to block the development of wind farms? That’s what they want, isn’t it? To promote the use of “green” forms of energy production? Are they just a bunch of tree huggers who look for an excuse to oppose everything just because they like to be contrary? Or do they have a point?

The environmental concerns about wind farms arise because the motion of the turbines results in the death of many flying animals, notably birds and bats. Most of the deaths occur because of collisions with the turbines, but they can also occur from a condition known as barotrauma. In the same way that human divers can develop the bends when they decompress by returning to the surface from sea depths too quickly, barotrauma occurs when the motion of turbine blades at wind farms create low-pressure zones that can cause the lungs of small animals to hemorrhage.

A legal basis for challenging the development of wind farms from an environmental standpoint arises particularly when the affected animals have a protected status under the Endangered Species Act. The first such case was Animal Welfare Institute v. Beech Ridge Energy LLC, which concerned the Beech Ridge Wind Energy Project along the Appalachian mountain ridgelines in West Virginia. The project was budgeted at some $300 million and expected to produce 186 megawatts of power, enough to satisfy the energy needs of 50,000 households in a typical year.

But the site was in the migratory path of the tiny Indiana bat, a species of bat that weighs only a quarter of an ounce. The Indiana bat has been designated as an endangered species since 1967, and its population has since that time reduced by about 50% despite that designation.

The court, in an order issued December 8, 2009, allowed the completion of 40 turbines whose construction had already begun, but ordered that those turbines could only be operated during the hibernation phase of the Indiana bat, a period of about three and a half months from November to March each year. If the turbines are to be operated at other times of the year, a permit is required from the Fish and Wildlife Service after it conducts a study on the impact of the wind farm on the bats. The process for obtaining a permit is currently ongoing; the Fish and Wildlife Service issued a Request for Information last week as one of the first steps in its investigation.

Subsequent to the decision, a settlement was reached between the parties that allows for construction of an additional 27 turbines, provided they are only operated at times of the day and year when Indiana bats are not expected to be flying.

In many ways, this result seems harsh. There are many calls to develop alternative forms of energy production and wind energy is an important one of these. And the operation of a large project that would supply energy for tens of thousands of households has been constrained to accommodate the schedule of a tiny animal that is rarely observed.

But this was just the first of what appears to be quickly turning out to be a large number of lawsuits challenging wind farms because of their impact on endangered species. Last month, a lawsuit was filed to stop the Cape Wind Project, an offshore wind farm planned in Nantucket Sound off Cape Cod in Massachusetts. This would be the nation’s first offshore wind farm, but the lawsuit alleges that it would endanger piping plovers, a protected species of bird, as well as endanger whales. Threats have been made to bring a lawsuit to stop the Garrett County wind project in western Maryland because of its impact on both the Indiana bat and the Virginia big-eared bat, another protected species. The Radar Ridge Wind Project in the State of Washington may be in jeopardy because of concerns about the migration patterns of the protected marbled murrelet. Wind projects in California are coming under increasing scrutiny because of deaths of whooping cranes at wind farms, one of the first birds to be listed as endangered under the Endangered Species Act. And there are many other examples gaining attention in the wake of the Beech Ridge decision.

There are other legal concerns related to wind farms and which have resulted in lawsuits, this time because of their impact on human beings. Noise from turbine motion is a common source of the complaints that lead to lawsuits. But even more interesting is turbine shadow flicker, an effect caused by the rotation of the turbines that produces a strobe effect when sunlight shines along a path that includes the turbines. Shadow flicker can cause eyestrain, headaches, nausea, and even induce epileptic seizures in some people.

But I will leave the discussion of this aspect of wind-energy lawsuits for another day.